For the Galaxia and mushroom small meaty foods. The plate coral probably would benifit from DT's photyplankton and if it will take them, frozen brine shrimp. Greenstar polyps are photosynthetic so you don't feed those.
Plates have a bit too large of feeder tentacles to feed on phyto (don't eat phyto), they enjoy larger bits of meat Honestly, none of your corals you have need phyto. Your micro life/infauna would enjoy it though.
Green star polyps... basically don't have a completely sterile tank (you really have to try to kill those guys)
Galaxia.. unsure they have small tenticles (but at night they can sweep out quite a distance.. so be careful where you place it!)
Mushroom & Plate, meaty foods (mysis or something)